function roll_over(img_name, img_src)
{
  document[img_name].src = img_src;
}


function wopen(url, name, w, h)
{
  w += 32;
  h += 96;
  var win = window.open(url,
  name,
  'width=' + w + ', height=' + h + ', ' +
  'location=no, menubar=no, ' +
  'status=no, toolbar=no, scrollbars=yes, resizable=no');
  win.resizeTo(w, h);
  win.focus();
}